1. Field of the Invention
The present invention pertains to a covered conduit box for use in allowing access to wiring for an apparatus such as a motor, wherein a cover of the conduit box maintains screws, used to secure the cover to a base of the box, captured therein upon disengagement of the cover from the base.
2. Description of the Prior Art
Heretofore various manners of maintaining screws captive in a structure have been proposed.
For example, the Slater U.S. Pat. No. 4,580,689 discloses an electrical outlet box having a pair of integral bosses that angularly align, engage and retain wiring device mounting screws therein. The bosses each have a throughbore for receiving the screws comprising in sequence a frustoconical surface, a first cylindrical surface having a diameter slightly larger than the crest diameter of the mounting screw thread, and a second cylindrical surface having a diameter slightly smaller than the crest diameter of the screw thread and slightly larger than the root diameter of the screw thread. The frustoconical and two cylindrical surfaces are coaxial, with the frustoconical and first cylindrical surfaces angularly aligning the screw substantially coaxially of the bore and engaging the screw to resist inadvertent removal of the screw from the bore, and the second cylindrical surface threadedly retaining the screw therein upon rotation of the screw along that surface.
Retaining clips and rings for use in maintaining screw engagement have also been proposed, as in U. S. Pat. No. 4,214,667 to Lass, U.S. Pat. No. 4,036,389 to Pate et al., U.S. Pat. No. 4,449,777 to Baribeau and U.S. Pat. No. 4,295,575 to Flachbarth.
Also, load absorbing screw engagement is proposed in the Greenwood U.S. Pat. No. 4,504,698 and a vandal proof secured nut and bolt engagement is disclosed in the Morris U.S. Pat. No. 4,167,197.
As will be described in greater detail hereinafter, the box and cover with captive screws therein of the present invention differs from structures previously proposed by causing captivity of a screw within a primary orifice for same, while at the time of engagement to a secondary body relative thereto, causing a torque action which acts upon screw thread to maintain the structures engaged.